A solid-state imaging device and an imaging apparatus that enable provision of a solid-state imaging device having superior color separation and high sensitivity are provided. The solid-state imaging device includes a semiconductor layer in which a surface side becomes a circuit formation surface, photoelectric conversion units PD1 and PD2 of two layers or more that are stacked and formed in the semiconductor layer, and a longitudinal transistor Tr1 in which a gate electrode is formed to be embedded in the semiconductor layer from a surface of the semiconductor layer. The photoelectric conversion unit PD1 of one layer in the photoelectric conversion units of the two layers or more is formed over a portion of the gate electrode of the longitudinal transistor Tr1 embedded in the semiconductor substrate and is connected to a channel formed by the longitudinal transistor Tr1.